000
FXUS62 KMFL 211745
AFDMFL

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MIAMI FL
145 PM EDT SUN SEP 21 2008

.AVIATION...VFR CONDITIONS WILL PREVAIL NEXT 24 HOURS ACROSS ALL
OF S FLA. SEA BREEZE CIRCULATION WELL UNDERWAY ALONG THE E CST SO
ALL SHRA HAVE DEVELOPED FAR TO THE WEST OF THE E TERMINALS AND
THIS WILL BE THE TREND FOR THE REMAINDER OF THE AFTERNOON HOURS. A
FEW TSRA MAY DEVELOP INTERIOR AND THEN MOVE INVOF KAPF AND HAVE
PLACE THIS IN THEIR TAF BTWN 20Z AND 00Z. IN ADDITION, W CST SEA
BREEZE WILL SET UP AROUND 19Z ALTHOUGH SOME MODEL GUIDANCE
SUGGESTS UP TO AN HOUR EARLIER BUT WENT WITH PERSISTENCE AS FLOW
PATTERN SIMILAR TO YESTERDAY. LIGHT E FLOW WILL RETURN AFT 00Z TO
02Z AT ALL SITES WITH VCSH SETTING UP ONCE AGAIN ALONG THE E CST.

30/KOB


&&

.PREV DISCUSSION... /ISSUED 1104 AM EDT SUN SEP 21 2008/

UPDATE...
NO MAJOR CHANGES WILL BE MADE TO THE FIRST PERIOD FORECAST THIS
MORNING...WITH EVERYTHING APPEARING TO BE IN GOOD SHAPE AT THIS
TIME. LATEST IMAGERY FROM KAMX INDICATES A DISSIPATING TREND IN
SHOWER ACTIVITY OVER THE ATLANTIC AND OFF SHORE GULF WATERS.
HOWEVER...EXPECT REGENERATION OF AT LEAST WIDELY SCATTERED
SHOWERS/THUNDERSTORMS OVER THE MAINLAND EARLY THIS AFTERNOON...AS
LOW-LEVEL DESTABILIZATION OCCURS. THIS IS ALREADY REFLECTED IN THE
CURRENT FORECAST...WITH NO CHANGES REQUIRED.

70/DD

AVIATION DISCUSSION... /ISSUED 749 AM EDT SUN SEP 21 2008/

AVIATION...MOSTLY VFR CONDITIONS WILL PREVAIL IN LIGHT EASTERLY
FLOW. ISOLD SHRA WILL MOVE ONSHORE OF THE SE CST THIS MORNING
WITH AND HAVE PLACED VCSH IN ALL E CST TERMINALS WITH THE
EXCEPTION OF KPBI. ONE SUCH SHRA WILL MOVE OVER KPBI THROUGH 13Z
AND HAVE ACCOUNTED FOR THIS BY INCLUDING A TEMPO GROUP FOR THE
FIRST HOUR. IN THIS FLOW, MOST CONVECTION SHOULD BE EAST OF THE
TERMINALS BY 18Z WITH THE POSSIBILITY OF ISOLD TSRA GETTING CLOSE
TO KAPF AFT 19Z AS THE W CST SEA BREEZE SETS UP. WIND FLOW WILL
BECOME DIMINISH AGAIN AFT 02Z.

30/KOB

PREV DISCUSSION... /ISSUED 349 AM EDT SUN SEP 21 2008/

DISCUSSION...A WEAK UPPER LOW OFF OF THE E FLA COAST DISSIPATES
TODAY AND ALLOWS THE MID ATLC RIDGE TO THE SE TO REBUILD
SLIGHTLY OVER THE AREA TODAY AND TONIGHT. MON...AS A STRONG LONG
WAVE UPPER RIDGE OVER THE GREAT PLAINS MOVES EASTWARD...AN UPPER
TROUGH BEGINS TO DEVELOP OVER NEW ENGLAND THAT EXTENDS SW INTO
THE TN RIVER VALLEY. BY TUE...THIS TROUGH DEEPENS...SHOVES THE
ATLC RIDGE SE ...WITH A CUTOFF UPPER LOW DEVELOPING OVER THE SE
U.S./N AND CENTRAL FLA PENINSULA WHICH WILL PERSIST INTO NEXT
WEEKEND.

FOR THE SHORT TERM...TODAY THROUGH TUE...SOME DRY SUBSIDENT AIR
ALOFT REMAINS OVER S FLA TODAY AGAIN CURTAILING THE CHANCES OF
RAIN. LOW POPS E WHICH GRADUALLY RISE TO THE W BUT REMAIN BELOW
NORMS. LIMITED E COAST POPS TONIGHT WHICH END IN THE EVE W. MON
THE ATMO -SPHERE BEGINS TO DESTABILIZE AND MOISTURE GRADUALLY
BEGINS TO INCREASE WITH A SLIGHTLY DEEPER EASTERLY FLOW WITH THE
TREND CONTINUING INTO TUE.

EXTENDED PERIOD...WED THROUGH SAT...ATMOSPHERE CONTINUES TO SLOWLY
DESTABILIZE AND MOISTEN AS UPPER LOW DEVELOPS OVER THE SE U.S.
POSSIBLE DIVERGENT FLOW ALOFT A FACTOR AND WEATHER BEGINS TO TREND
FROM W TO E IN A REVERSAL OF THE NORMAL S FLA LATE SUMMER/EARLY
FALL PATTERN. THE A LARGE TROUGH OVER E U.S. THE GLOB OF WEATHER S
OF PUERTO RICO IN THE CARIBBEAN SHOULD PULL NORTHWARD AND REMAIN
WELL E OF S FLA. THE UPPER LOW WILL GENERATE A SURFACE LOW OFF OF
THE NC COAST WHICH MAY PULL A FRONT?...AT LEAST POSSIBLY COOLER
AND DRIER AIR OVER S FLA NEXT WEEKEND. ONE CAN HOPE.

MARINE...EASTERLY WINDS LESS THAN 15 KNOTS WITH GULF STREAM SEAS
UP TO 4 FEET AT TIMES WHEN WINDS DEVELOP A NE TREND TODAY
THROUGH TUE. BY WED AND THU...LOW PRES DEVELOPING OVER THE THE
ATLC OFF OF THE SE U.S. COAST MAY BEGIN TO GENERATE SOME SWELLS
THAT MAY IMPACT MAINLY THE PALM BEACH WATERS WITH SEAS TO 7 FEET.
A SMALL SWELL STILL AFFECTING PALM BEACH WATERS TODAY.

FIRE WEATHER...NO FIRE WEATHER CONCERNS THROUGHOUT THE FORECAST
PERIOD AS MINIMUM RH VALUES REMAIN SUFFICIENTLY HIGH.

&&

.PRELIMINARY POINT TEMPS/POPS...
WEST PALM BEACH  77  88  76  88 / 20 30 30 40
FORT LAUDERDALE  80  89  78  87 / 20 30 30 40
MIAMI            78  89  77  88 / 20 30 30 40
NAPLES           75  91  74  90 / 20 30 30 50

&&

.MFL WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
AM...NONE.
GM...NONE.
&&

$$